Endocrine Abstracts

Section 1: Case history: A 69-year-old female with a past history of treated hypertension and Graves’ disease presented to the emergency department with a two-day history of headaches, vomiting, confusion and difficulty swallowing following a recent holiday in Spain. She had clinical meningism and a diagnosis of meningitis was made.

Section 2: Investigations: After an initial CT scan of her head was reported as unremarkable, a lumbar puncture was performed. A CT scan of her head was repeated ten days later as she reported worsening headaches. The second CT scan was followed by a contrast enhanced MRI of her head as the scan revealed an abnormality in her pituitary fossa.

Section 3: Results and treatment: The MRI of the head confirmed a peripherally enhancing lesion in the pituitary extending to involve the hypothalamus, with surrounding oedema, consistent with a pituitary abscess. In retrospect, the previous two CT scans also showed the abnormalities. The lumbar puncture revealed turbid CSF with a total WBC of 2180, 80% of which were neutrophils, consistent with bacterial meningitis. PCR was negative for meningococcus and pneumococcus. CSF cultures were sterile. She was treated with intravenous ceftriaxone and underwent a transsphenoidal drainage of pus from the pituitary fossa. She had transient diabetes insipidus but was otherwise eupituitary. The histology did not show evidence of Rathke’s cleft cysts or craniopharyngiomas.

Section 4: Conclusions and points for discussion: Pituitary abscesses are very rare, with around 200 cases reported to the best of our knowledge. Often, they present sub-acutely with hypopituitarism and a mass lesion. They present with systemic signs and symptoms of infection in less than 20% of cases. Irreversible pan-hypopituitarism is common. Pituitary abscesses may occur in either an anatomically normal gland or in the context of Rathke’s cleft tumours or craniopharyngiomas. The mechanisms of infection in the pituitary are believed to be haematogenous seeding or rarely contiguous spread from sphenoiditis. Our patient had a number of unusual features including acute presentation with meningism, systemic features of infection and transient diabetes insipidus. She has done well, being eupituitary on followup with no long-term sequelae after five years. A pituitary abscess is a differential diagnosis of a pituitary lesion, often associated with pan hypopituitarism. It can be misdiagnosed as an adenoma as it infrequently presents with features of infection. A correct diagnosis will result in appropriate antibiotic treatment, drainage and prognostication with regards to endocrine sequelae.